A significant fraction of car accidents and a significant fraction of accident fatalities occur at intersections. Certain intersections are more dangerous due to the poor visibility with respect to cars approaching on cross roads from the perspective of a driver in a car stopped at the intersection. This may be due to the curvature of intersecting roads or due to the presence of objects such as parked cars, a building, a fence, a wall, trees or hedges near the intersection. The stopping point for cars at intersections is selected to keep stopped vehicles spaced at a safe distance from traffic on cross streets, but unfortunately may not afford a clear view of such traffic from the perspective of the driver's seat.
In the past there were efforts to address the problem by placing a wide angle camera at the front of a vehicle and routing the video feed from the camera to the vehicle's navigation display.
Additionally there have been efforts to automatically issue warnings to drivers. For example, U.S. Patent Publication 2015/0051753 to Kawamata et al. discloses providing a level of driving assistance in the form of warning lights or audio that is dependent on whether or not obstacles are detected at an intersection. Obstacles are detected using sound emitted by the vehicle and a set of microphones.